fonseca



Feb. 26, 1929. 1,703,854

E. L. FONSECA PILOT LIGHT CQNTROL Filed Feb. 20, 192.6 2 sheets-sheet 15 5 I I I I I J MMM ATTORNEYS Feb. 26, 1929. A 1,703,854

5* E. L. FONSECA PILOT LIGHT CONTROL Filed Feb. 20,:1926 2 Sheets-Sheet2 l TOR Z1144 m,

ATTORN EYS Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

EDW'ARD L. FONSEOA, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE WILGOLATORGOMIANY, OF NEVJARK, NEW JERSEY, A CORPORATION OF DELAWARE.

PILOT-LIGHT CONTROL.

Application filed February This invention relates to thermostaticcontrol devices and has to do more particularly with the thermostaticcontroller which governs the supply of fuel to a'main burner inaccordance with conditions which prevail at a pilot burner by which thegas flowing from the mainburner is ignited. As the inven ticn is ofspecial utility in automatic gas heaters, that adaptation of it will bedescribed, but it is to be understood that such use is merely typical.

In gas heaters of the automatic type, such, for example, as thosecommonly used in resi dences for supplying hot water, the supply of gasto the main burners is under the control of a thermostatic mechanismwhich is responsive to changesin temperature in the body of liquid beingheated. This mechanism actuate-s a valve in the gas supply main, andwhen the liquid cools to a predetermined low temperature. the mechanismopens the valve and flows to the burners. Similarly, when a.predetermined high temperature is reached, the valve isclosed and theburners are extinguished. In order that the burners may again be lightedwhen occasion arises, is necessary to maintain a pilot light which isconstantly burning, at some point adjacent the burners. This is a smalliiame and it sometimes accidentally extinguished, as, for instance, bydrafts. If the temperature of the liquid should fall to the point atwhich the main valve is opened, while the pilot light is out, gas willescape free y from the main burners, and this may lead to seriousaccidents. It is therefore desirable inheaters of this type to provide acontrol mechanism to govern the supply of to the main heater burnerswhich is responsive to the heat'generated by the burning of the pilotlight so that no gas can flow 20, 1926. Serial No. 89,641.

placed near the other end of the line. The element includes abi-metallic strip which is arranged to have a free end which moves inaccordance with temperature changes, and this moving'end of the strip isconnected to the movable member of the valve. The valve opens and closesagainst the gas pressure in the main, and the arrangement is such thatwhen the pilot burner is lighted the end of the strip moves to raise themovable part of the valve from its seat. Such movement ofthe valve partis opposed by the gas pressure in the main acting upon the upper surfaceof the part, and an appreciable stress is put upon the strip before thegas pressure is overcome. lVhen this occurs, the movable part of thevalve suddenly snaps open so that the full opening of the valve isaccomplished, and as a result the entire main beyond the valve is atonce filled with gas andno explosive mixture of gas and air is produced.Similarl if the pilot light burner is to be extinguished, the movablepart of the valve is again closed with a snap action. A pressure isexerted on the movable part of the valve, due to the friction of the gasflowing past it, and also to the velocity head pressure of the gasimpinging on the part. As the movable part approaches its seat, the sumof these pressures builds up rapidly and overcomes the cantilever springresistance of the thermostatic element until, when the part closelyapproaches its seat, is is suddenly seated with a snap action, so thatthe valve is thus completely closed and again an explosive mix ture isprevented from being delivered to the burner.

The new pilot light controller may be used with either a blue or ayellow flame pilot, and both types of burner will be described.

For a better understanding of the invention, reference may be had to theaccompanying drawings, in which Fig. 1 is a side view, partly insection, showing the new control mechanism in its relation to the gassupply main, and the heater burner,

Fig. 2 is a view largely diagrammatic, showing the, completeinstallation including the controller responsive to temperature changesin the body of liquid or chamber to be heated,

. controller, and

Fig. 3 is a View in perspective, showing the mounting of thethermostatic controller inrelation to the pilot light burner, L

Fig. 4 is a side view .ofa slightly modified mounting,

Fig. 5 is a view of a modified type of burner which may be used with thecon-' troller,

'Fig. 6 partly insection, of a modified form of the Figs. 7 and 8 arediagrammatic views showing the piping arrangements.

Referring now to the drawings, the gas heater is generally designated10, and consists of a casing 11 in which is a coil 12, heated by burners13. The coil is in communicati'on with a tank 14, so that liquid fromthe tanl: continually circulates through the coil. The burners 13' areof any standard type, and are supplied with gas from a manifold15connected to a main 16. In this main is a valve 17 which is controlledby a thermostatic controller generally designated 18 and having atemperature-responsive element 19 projecting into the tank 14. The valve1'? is opened and closed by the thermostatic controller in accordancewith variations in temperature in the body of liquid. The supply -main16 is also provided with a manually. operated valve 20' and bet-weenthese valvesis a third valve'21, actuated by a thermostatic mechanismgenerally designated 22, which operates in response to heat generated bythe burning of gas inthe pilot light burner23.

'Asshown more clearly in Fig. 1, the valve 21 is, in general, ofstandard construction, having a seat 24 on which lies a ball 25. As theball is raised from its seat, gas from the main may pass through thevalve to the main heater burners, under the control of the device 18. Onthe top or" the body of the valve is a bushing 26 threaded in positionand terminating-at its lower end in a tubular extension 27, throughwhich are orifices 28. In the upper end of the bushing is threaded a 1pipe 29,11eld in place by an adjusting locl: nut 30, bearing against theupper end of the bushing 26. The interior oi the tube 29 is incommunication with the main in front of the valve, in part through theorifices 28. The ball 25 of the valve 21. is movable up and down in-thetubular extension, which acts as a guide for the ball. Mounted in theside of the tube 29 at some distance above the valve 21. is a fitting31, having a passage 32 inconnnunication with the interior of the tube29. This fitting has a passage 33 having an opening at its lower endcontrolled by a needle valve 34 which has a shank'35 threaded into thelower end of the fitting and held in adjusted position by a nut 36.Threaded on the fitting 31 is a burner tube 37, having a plurality ofair inlet openings is aview partly in elevation and 38, a short distanceabove the end of the passage 33, and at its upper end the burnertube'has a series of burner orifices 39 arranged in' a line. The line oforifices partially encircles the tube, as indicated at 40, and thenextends up in a straight line along one side, as indicated at 41.

The valve 21 and the tubes 29 and 37 are so positioned that the orificesat the top of the tube 37 lie close to the upper end of the burners 13so that when the pilot light burner is lighted, its flames will causeany gas flowing from the burner 18 to be ig nited.

Threaded on the end of the tube 29 is an elbow 42, provided with a splitextension 43 which clamps the tube 37. W'ithin the elbow, secured in anyconvenient manner, as by rivets 44, is an L-shaped bracket 45, to whichis secured one end 46 of a U-shapcd thermostatic element 47 This elementis made of two metals in the ordinary manner, and its free end 48 isplaced above the tube 29. The element is so arranged that when exposedto heat the free end 48 moves toward the fixed end secured to thebracket. The element is partially enclosed in a closed tube 49, threadedin the fitting 42.

Disposed within the tube 29 is a rod 50 secured by means of a nut 51 tothe ball 25. This rod extends through an opening in the upper end of theelement and carries a washer 52, held in place by a cotter-pin 53, abovethe end of the element. Below the element is a washer 54, against whichbears one end of a light spring 55, encircling the rod 50. The lower endof this spring bears against a washer 56 held in place by a cotter-pin57. It will be seen that with this arrangement, when the element isheated so that the bow contracts, the end of the element will engage theupper washer 52 and lift the rod, thus causing the ball 25 to be freedfrom the seat 24. When the element is cold so that its two legs aresprung apart, it will exert a downward pressure which will betransmitted through the spring 55 to the washer 56, thus causing theball to seat. It, after the ball is seated, there is any furthertendency of the element to expand, this is taken up by the collapse ofthe spring 55.

It will be seen that the ball is exposed to the pressure of the gas inthe main 16 and consequently when the thermostatic element is heated andits free end begins to rise, tending to lift the ball from its seat,such movement will be opposed by the gas pressure acting upon the upperside of the ball. This pressure will resist the movement oi? the elementand tend to hold the ball on its seat until the element is placed undera considerable tension. hen the tension slightly exceeds the pressure ofthe gas, the ball is lifted from its seat and the gas pressure becomingsubstantially equalized on both sides of the ball, the latter is free tobe moved by the element. As the element is still under some tension,this results in the ball being lifted quickly a substantial distancefrom the seat so that the valve has a snap action in opening. Similarlyin closing, the free end of the element tends to force the balldownwardly on its seat, and this movement is assisted by pressurederived from the impingement of the gas upon the top of the ball, andalso by the friction of the gas past the ball. The forces acting on theball build up r. idly as the ball approaches its seat and .inallyovercome the cantilever-spring resistance of the thermostatic strip andcause the ball to seat with a snap action. By this arrangement,therefore, the snap action of the valve in opening andclosing insuresthat that part of the main 16 beyond the valve is either in fullcommunication with the gas supply, or else completely out off from it,and thus small amounts of gas are not permitted to How to the burner,resulting in mixture with the air in the burner and producing anexplosion.

In the form shown in Fig. 1, the burner tube. 37 is clamped in positionrelative to the tube 29, by a clamp 13 which forms a part of the elbow42. l/Vith this arrangement the thermostatic element 47 is directly connected through. metal to the tube 37, from which the gas is supplied tothe pilot light flames. When the heater is to be ut in operation themain valve 20 is manually opened and a sufiicient quantity of gas willflow from the main through the tubes 29 and 37 to the pilot lightorifices. As the gas burns it heats the upper end of the tube 37 and theheat is conducted through the metal parts directly to the element sothat in a short time, the free end of the element moves to open thevalve 21 and thus admit fuel to the burners 13, these burners beingignited by the flames at the end of the tube 37. The arrangement of theparts is such, however, that although a good i nition of the mainburners lii is provided for, the thermostatic element is placed aconsiderable distance from these burners so that the action of thethermostatic strip in it is not materially affected by the main burners.Similarly, by altering the length of the tubes 29 and 37, the valve 21can beplaced at any convenient distance relative to the burners 13, andthe opening of the valve 21 may easily be regulated by screwing the tube29 111 or out of the bushing 26. The tube 29 has a fine thread at itslower end to provide for an exact adjustment of the lift of the ball 25.

Another advantage of the present construction is that the thermostaticcontroller for the pilot light burner may be placed either vertical,horizontal, or at any inter mediate angle. In some installations, it isdesirable that the pilot burner should extend vertically, while inothers the most convenient arrangement is to have the pilot burner liehorizontal in the chamber in which the main heater burners are placed.The present device is capable of installation in any desired way, andfurthermore the line of fiames 39 can be varied in any way that may berequired by the peculiarity of the installation. The pilot light burnerburns with a blue flame which may be conveniently adjusted by means ofthe needle valve without reference to the other parts of the device, andthe burner is so arranged-that it will operate on as low asthree-quarters to one cubic foot of gas per hour. Since this burner isburning at all times that the heater is in use, it is essential that itshould censume only a small quantity of gas, and that the controlmechanism should be sensitive under such conditions. It is alsoessential that the controller should operate quickly when the pilotlight goes out so as to prevent loss of gas. The present constructionaffords both advantages, and the amount of gas consumed is so small thateven though the burner should be extinguished, can escape from it for along time before a quantity has collected in the heater which would bedangerous.

In the construction illustrated in Fig. 4, the upper end of the burnertube 37 is clamped to the tube 29 by an ordinary twopart clamp 58. Inthis type of construction the line of orifices 39 extends dowmvardly asat 59, so that these flames impinge directly upon the end of the elbow4.2. This construction is alternative to that previously described, andeither one may be employed as desired. The first constructionispreferred, however, as it insures a direct con-' impinging upon theelement housing.

In Fig. 5 there is shown a slightly modified mounting for the burner andcontroller, and in this type the burner tube 37 is disposed in a bracket43, extending from the housing of the thermostatic strip, as shown in 1.Extending from the lower part of this housing is a bracket 60 carrying anozzle tube 61 which may be connected at its lower end to a pipe leadingto the supply. The end of the nozzle is spaced from the lower end of thetube 37, and thus gas flowing from the nozzle into the tube induces airwith it and by proper regulation of the height of the nozzle withreference to the lower end of the tube, a flame of the desired charactermay be obtained. In other respects this construction is similar to thatpreviously described. I

In Fig. 6 there is shown a modified form of construction which isdesigned for great compactness. In this form of controller the valvehousing 21 has an opening in its upper end in which is threaded a tube62. .The

tube terminates at its upper end in a smaller tube 63, the tube 63terminating atits upper end in a burner of the usual construction,including a row of outlets (i l and a disc 65 above the outlet. Withinthe tube 62 is a bowed thermostatic element 66, one end of which may besecured in any convenient rigid manner, as by being riveted as at 67, tothe valve housing. The free end 68 of the element extends down into thevalve chamber and directly attached to it is the ball 69 cooperatingwith the seat 70. The operationof this form of the controller-issimilarto that previously described. hen the pilot light is burning thevalve is oil? its seat and permits the flow of gas therethrough. As soonas the pilot light is eX- tinguished, the cooling or" the thermostaticelement causes the valve to seat and prevent further flow of gas to themain burner.

In Figs. 7 and 8 are shown piping installations showing the devicediagrammatically as it is actually used. In the installation shown inFig. 7, the main 16 contains the manually operated. shut-oil valve 20,beyond which is a T 71. Beyond this T is the valve operated by thethermostatic elementrwhich enters the tank 1 Beyond the valveli' is thevalve 21 from which the line .16 extents to the burner manifold 15. Thepilot burner 23 is supplied with gas by a line 72connected at its upperend to the T 71 so that with this arrangement the pilot burner controlsthe flow of gas by means of a valve placed directly in front of the mainburner, but the pilot burner itself receives gas from the main in frontof the valve controlled by the thermostatic element exposed to thetemperature within the tank, Vith this arrangement the piping is greatlysimplified because the line 72 may be of small size and it is notnecessary to lead the main supply pipe back upon itself in the mannerillustrated in Fig. 2. The installation shownin Fig. 7 may be usedwhenthe gas is supplied to the main burner from a main which runs overhead.7 r

In the construction shown in Fi 8 the 1 t) 7 piping installation is onewhich may be con- I veniently used when the heater is above the operatedvalve 20 and the valve controlled by the main thermostatic mechanism,and with the arrangement shown either in Figs. 2, 7, or 8, it will beobserved that the pilot burner receives gas from the supply main moaeaaat a point in advance of the valve controlled by the thermostaticelement Within the tank. In the constructions shown in 2 and 7, thepilot control mechanism includes a valve which cuts oil the supply ofgas prior to its passing through the thermostatically controlled valve1?, while in the construction shown in Fig. 8, the pilot lightcontroller cuts oil? the gas at a point between the burner and thethermostatically controlled valve 1?. Either arrangementis satisfactory,so long as the pilot burner receives a supply of gas which is in no wayfllTQCtGQl by the adjustment-of the valve 17.

it will be observed that in any oi the forms of controller illustrated,the valve actuated by the pilot light controller is moved by a directconnection with the thermostrtic element. This arrangement permits aconsiderable valve movement which aii'ords easy adjustment and thereforeextreme sensitivity of operation. Furthcrn'iorc, the olilicts oi largeteinljicrature changes on the element are llflllllll'llZQd. Theadjustment of the controller is a simple operation and merely involvesthe loosening ol. the nut 30 and the turning of the burner and housingas a unit, one or more revolutions. The housing is threaded into thebushing 26 with a line thread. so that a com ilcte revolution of theburner and housing results in only a slight movement of the valve towardits scat, thus permitting close and accurate adjusti'ncnt to be made.The controller is also adaptable for a. wide variety of uses, and it maybe arrai'iged For use in any installation, regardless of the directionin which the pilot burner tube is to extend. from the si as main. Theburners may be placed in a vertical, horizontal, or inclined position,and by altering the length of the tubes and the llamc track, therequirements of any particular installation may easily be met. lViththis construction the'main burner is so placed that it does notn'iaterially affect the temperature of the thermostatic element, and at.the same time good ignition is provided. liurlhcrmorc, the adjustment oithe blue flame from the pilot is readily made. The valve employed isonein which there is a inclal-to-mclal contact between the seat and themoving part, and the valve is entirely scaled so that the escape o'l. isprevented. There are no joints or connections in which friction willdevelop, and furthermore no com plicated lever system, such asordinarily employed in devices ol this cluiractcr, is necessary, owingto the fact that the movable part of the valve is directly connected andmoved by the thermostatic element. The spring take-up in the connectionbctween the element and the ball of the valve prevents injury of thedelicate thermostatic element, and by reason of the absence of theconnecting links or pivoted levers,

the parts cannot corrode and thus stick valve, comprising a housingadjustably mounted in the casing of the valve and extending therefrom toa point adjacent the pilot burner, a thermostatic element mounted withinthe housing and movable therewith as the housing is adjusted withreference to the valve casing, this element being continuously exposedto the temperature developed by the pilot burner flame but outside thezone of temperature produced by the main burnenand a positive connectionWithin the housing between the element and the valve whereby the elementmaintains the valve open while the pilot burner is burning and shuts thevalve when the pilot burner is extinguished.

2. In a gas heater, a gas supply main,

a main burner receiving gas therefrom, a valve in the main controllingthe flow of gas to the main burner and including a casing and seat and amovable part cooperating with the seat, a tube having flame orificesserving as a pilot for the main burner, a housing mounted in the casingof the valve vand having a portion at its end extending at right anglesto the axis or the housing, the said portion being conductivelyconnected to the pilot burner tube, a temperature-responsive elementwithin the said portion of the housing and having a part movable todifierent positions in accordance with temperature variations, thiselement being out of the zone of tempera ture developed by the mainburner but receiving heat from the pilot burner, and a connection withinthe housing extending from the said movable part of the element to themovable part of the valve, the ele ment and the connection being suchthat the valve is held open while the pilot light is burning and isclosed when the pilot burner is extinguished.

3. In a gas heater, a gas supply main, a main burner receiving gastherefrom, a valve for controlling the flow of gas to the main. burner,ahousing connected to the valve, a temperattire-responsive element inthe housing, a pilot burner tube lying outside the housing and havingflame orifices for directing flames to ignite the main burner, thetemperature-responsive element lying outside the zone of temperature developed by the main burner, a connection between :the housing and theburner tube for supporting the tube in relation to the housing and alsofor conducting heat from the burner tube to the housing and element, anda connection between the element and the valve whereby the valve isopened when the pilot burner is-lighted and closed when the pilot burneris extinguished.

a. In gas heater, the combination of a supply main, a heater burnerconnected to the main, a valve in the main for controlling the flow ofgas to the said burner, a pilot burner tube having flame orifices forigniting the main burner, a housing connected to the valve, the pilotburner tube lying outside the housing and being secured thereto andsupport-ed thereby, a temperature-responsive element Within the housinghaving a part movable to different positions in accordance withtemperature variations, this element being exposed to the temperaturedeveloped by the pilot burner but out of the zone of temperaturedeveloped by the main burner, a connection between the movable part ofthis element and the valve such that the valve is open when the pilotburner is lighted and closed when the pilot burner is extinguished, andmeans for regulating the action of the element on the valve by movingthe housing and pilot burner bodily with reference to the valve. I

5. The combination of a gas supply line, a main burner receiving gastherefrom, a valve for controlling the flow of gas to the main burner, apilot burner for the main burner, and means by which the pilot burnerthermostatically controls the operation of said valve, comprising ahousing connected to the casing of the valve and also connected to thepilot burner at a point near the flame thereof, the housing serving as amounting for the pilot burner and receiving heat therefrom conduetivelythrough the connection, a thermostatic element within the housingreceiving heat from the pilot burnor but out of the zone of temperaturede veloped by the main burner, and a direct connection within thehousing between the thermostatieelement and the valve whereby theelement acts to hold the valve open while the pilot burner is burningand to close the valve when the pilot burner is extinguished.

6. The combination of a gas supply line, a main burner receiving gastherefrom, a valve for controlling the flow of gas to the main burner, apilot burner tube receiving gas from the line and having a flameadjacent the main burner to ignite the latter, 7

static element within the housing exposed to the temperature developedby the pilot burner, but out of the zone of temperature "developed bythe main burner, anda con- H nection within the housing between theelement and the valve, such that the element holds the valve open whenthe pilot burner is burning but closesthe valve when the pilot burner isextinguished.

7. The combination of a gas supply line,

a main burner receiving gas therefrom, a

valve for controlling the flow of gas to the main burner, a pilot burnertube'receiving gas from the line and having flame orifices adjacent themain burner, and means by which the pilot thermostatically controls'theoperation cit the valve, comprising a housing connected to the valvecasing, this housing having an angularly disposed end portion, aconnection between the burner tube and the housing'by which the housingsupports the burner tube, the support providing means for conductingheat developed by the pilot burner to the housing, a thermostaticelement within the said end portion of -;the housing having a partmovable to different positions in accordance with temperaturevariatiens,this element receiving heat developed by the pilot burner conductivelybut lying out of the zone of temperature developed by the main burner,and a direct connection within the housing between the valve and themovable part of said element whereby said element maintains the valveopen while the pilot burner is lighted, but closes the valve when thepilot burner is extinguished.

8. In combination with a gas heater having a main burner and a pilotburner adapted to thermostatically control the operation of a valve inthe gas supply main;

a housing comprising two connected per-'- tions extending at an angle toeach other, one of said portions containing the temperature-responsiveelement and the other portion connecting the first named portion withthe casing containing the thermostatiezzily' controlled valve andenclosing the connecting member between the temporalure-responsiveelement and the valve, said first named portion having a part connectingit to the pilot burner.

9. In a gas heater, the combination of a pilot burner tube, a housingenclosing a temperature-responsive element and a mechaniical connectionleading therefrom to a fuel valve of the heater, said element beingdisposed near the pilot flame issuing from said tube but at :1V distancesuflicient to prevent EDXVARD L. F ONSECA.

